feat(euler): 48 - self powers

challenges/euler/readme.md

@@ -59,7 +59,7 @@ The source code can be found in the [src](src) directory. My thoughts about some
 -   [ ] 45 - Triangular, pentagonal, and hexagonal
 -   [ ] 46 - Goldbach's other conjecture
 -   [ ] 47 - Distinct primes factors
--   [ ] 48 - Self powers
+-   [x] [48 - Self powers](src/48%20-%20Self%20powers.ts)
 -   [ ] 49 - Prime permutations
 -   [ ] 50 - Consecutive prime sum
 -   [ ] 51 - Prime digit replacements

challenges/euler/src/48 - Self powers.ts

@@ -0,0 +1,21 @@
+// The series, 1^1 + 2^2 + 3^3 + ... + 10^10 = 10405071317.
+// Find the last ten digits of the series, 1^1 + 2^2 + 3^3 + ... + 1000^1000.
+export = {};
+
+const calculateSeries = (upperLimit: number): bigint => {
+    let sum = BigInt(0);
+
+    for (let i = 1; i <= upperLimit; i++) {
+        sum += BigInt(i) ** BigInt(i);
+    }
+
+    return sum;
+};
+
+const lastNDigits = (number: number | bigint, n: number) => {
+    const string = number.toString();
+    return parseInt(string.substring(string.length - n));
+};
+
+// Output
+console.log(lastNDigits(calculateSeries(1000), 10));

challenges/euler/tsconfig.json

@@ -1,6 +1,6 @@
 {
     "compilerOptions": {
-        "target": "es5",
+        "target": "es2020",
         "module": "commonjs",
         "outDir": "build",
         "esModuleInterop": true,